(1) Field of the Invention
The present invention relates to a semiconductor wafer mount apparatus for joining a semiconductor wafer, which has been subjected to a back grinding process, to a ring frame through a supporting adhesive tape (dicing tape) such that the ring frame supports the semiconductor wafer, thereby manufacturing a mount frame.
(2) Description of the Related Art
Semiconductor chips are obtained from a semiconductor wafer (hereinafter, simply referred to as “wafer”) through the following steps: a step of joining the wafer to a supporting adhesive tape joined to a ring frame such that the ring frame supports the wafer; a step of separating a protective tape joined to a front face of the wafer; and a step of subjecting a dicing process to the wafer so as to divide the wafer into the semiconductor chips (refer to, for example, JP-A 2002-343766).
Recently, a wafer is made thinner in response to needs for size reduction and high-density package as to an electronic device. However, a wafer made thin so as to have a thickness of several tens of micrometers becomes cracked or chipped readily due to an influence of warpage or local stress. Consequently, there is a high possibility that such wafer is damaged in a back grinding process where a working external force is acted on the wafer. In particular, the wafer, which has been made thin in the back grinding process, is readily susceptible to damage in handling. In order to avoid such disadvantage, there is the following proposition. That is, a center of a wafer is ground in a back grinding process to form an annular convex portion at an outer periphery of the wafer; thus, the wafer is allowed to have rigidity. In other words, the wafer is processed so as to be less susceptible to damage in handling.
In a case that semiconductor chips are obtained from the wafer, further, the wafer is joined to a ring frame through a supporting adhesive tape in order to prevent the semiconductor chips from being scattered and to reinforce the wafer. However, there is a problem that the ring frame cannot support the wafer with good accuracy due to presence of the annular convex portion.